you ask in an earlier post what kind of power generation the other schools were teaching. At the time I was in GTI (former TAGB) and they were teaching waist-twist and reaction hand. Around that time there was also a very patronising, butt-licking article in UK MA press about someone being taught 'true TKD', not 'outdated waist-twist'.

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See how well I block your punches with my jaw!!

Yeah, but the pulling back/chambering is also to add power (apparently). If you look at something like Wing Chun or boxing, the use of the chamber/reaction isn't as pronounced (if at all), whereas in TKD (especially waist twist) it is used to generate power as well.

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See how well I block your punches with my jaw!!

I think the studies were bias; an ITF school trying to prove that SW is better. Did anybody in the study actually hit harder without SW? And that after all the punches were done they just averaged it? I would be more readily to believe such a thing if the participants were all of equal height and weight. All had equal years of practice in their arts and included ITF, WTF, Karate, Boxers, etc. In fact the boxer probably could hit harder which than I guess would prove that all other punching arts are less; correct?

The bias in the study was not so much that the school was trying to prove that SW is better, the bias was in using only ITF practitioners who were used to doing the sinewave so were naturally better at it than using the hip twist.

A poster "Martialist" on another Forum had this to add about the Sine Wave

"Look, Honestly, I did the SINE WAVE for 10+ years. It is useless. I met spoke with a real close friend(Grandmaster Kim Bok Man) of General Choi and he stated that he thought that sine wave was useless. He approached the General before his passing and and told him. General Choi agreed with him and wanted to revert, take out, the Sinewave technique out of Taekwondo. But the ITF and other related federations were too big and indoctrinated, and basically to late to change because of General Choi's I'llness at that time.

If you don't believe me look up Master Kim Bok Man. He is basically one of the handful surviving members of original Korean Martial Art and it's transformation into Tae Kwon Do in the late 40's to 50's.

Seriously dude, No need to explain something that literaly has no explanation to Really, SINE WAVE was just made up and justified by General Choi all for making it look unique which he did very well. I did it for 10+ years and I know first hand that it's BullS***! You will have guys try to justify it any way they can but if you have an open mind you will understand that it just does not make sense...

I teach my style TKD and the sinewave is completely taken out of my curriculum....

Taekwon!"

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A man is but the product of his thoughts what he thinks, he becomes.

Dobber-san speaks the truth! I also did sine-wave. All that rising and falling was just wasted movement. I always thought it was a silly way of power generation. Totally unrealistic and certainly unusable in a self-defense situation.

Since I was asked to contribute to this thread by another poster I will add my 2 cents worth on the sine wave, from a physics perspective:

There is a concept in Tae Kwon Do, introduced by General Choi Hong Hi called the sine wave. It has been introduced as part of a scientific theory that claims to use physics to explain the use of a bobbing up and down motion combined with a forward movement to produce power instead of using the hip twist that is used by just about every other martial art out there. General Choi was a great man and a great martial artist but he was no scientist. Here is where the sine wave concept breaks down:

The equation given in the encyclopedia on page 47 of volume 2 is;

P = 1/2mv2

Where P = power

m = the mass

v = velocity.

However this is not the scientific formula for power, it is the formula for kinetic energy. Not power. Power would be the change in kinetic energy divided by time.

Another formula that has been used on a school’s website is;

P = 1/2mv2 + mgh

Where; mgh = 0 for no sine wave.

g = the acceleration due to gravity and h is the height.

This formula is used to attempt to show that a downward motion affects a horizontal motion. The + sign in the formula indicates that the 2 terms are independent of one another (one does not affect the other), if they were dependent then the terms would be multiplied. This is a valid equation for the total energy of a strike but only applies (when mgh does not equal 0) to movements that have a downward component, e.g. a downward punch or low section side kick. It is an accepted scientific theory that for objects moving under the influence of gravity, the horizontal and vertical components of the movement do not affect each other.

Another correct formula for power is;

P = W/t

Where W = work done and t = time;

By eliminating time (making it =1unit in seconds, minutes etc.), concentrating on the RHS of the equation and using the definition of work you have:

W = F*d*cos(theta)

Where F = the applied force, d = the distance moved and cos(theta) = the cosine of the angle of movement in relation to the applied force. A cosine wave is just a sine wave shifted by 90 degrees. For any angle smaller than 90 degrees or larger than 0 degrees cos(theta) = <1, which can be seen when dragging an object along the floor by a rope. When the rope is at an angle it is harder to move the object than if the rope was along the ground. For an angle of 90 degrees (the dropping of the hips in the sine wave movement) cos(theta) = exactly 0. In other words the pure downward motion contributes absolutely nothing to the power generated horizontally.